Aspects of Preheating and Higgs Cosmology

September 10, 2018
11:30am to 12:30pm

IFT Seminar Room/Red Room

Specialist level
Francisco Torrentí

IFT Seminar Room/Red Room


In this thesis we study several aspects of the out-of-equilibrium dynamics of the Universe after
inflation. The first part is focused on preheating: an explosive production of particles due to nonperturbative
effects. We do a fitting analysis of parametric resonance for chaotic inflation models.
By using classical lattice simulations, we parametrize the main time scales, energy fractions, and
field spectra, in terms of all circumstances and parameters. Preheating is also a powerful source of
primrordial gravitational waves (GW) in the early universe. We have parametrized the frequency
and amplitude of the peaks in the GW spectra, as well as obtained predictions for the GW signal
today. The second part is focused on Higgs Cosmology. In particular, we have studied the postinflationary
decay of the Standard Model Higgs condensate. After inflation the Higgs oscillates,
transferring most of its energy to gauge bosons via parametric resonance. We have studied this
process with lattice simulations, and have characterized in detail the evolution of the Higgs and its
decay products. We have obtained a master formula for the Higgs decay time as a function of all
unknowns, as well as studied the production of GW in this process. We have also studied the
implications of a non-minimal Higgs-curvature coupling for Higgs vacuum stability after inflation.